When you walk into Tracy Morgan's Nov. 11 concert at St. Petersburg's Mahaffey Theater, you'll have to hand over your cellphone. An attendant will lock it up in a little pouch, give it back to you, then unlock it at the end of the night.

It's the first appearance in Florida by the San Francisco startup Yondr, which seeks to create phone-free experiences at concerts and special events "where people can be swept into a shared mood," said founder and CEO Graham Dugoni.

Since launching in 2014, Yondr has provided pouches for concerts by artists like Guns N' Roses, the Lumineers, Alicia Keys, Louis C.K. and Dave Chappelle. But they've also found a foothold in school systems, manufacturing plants, workplaces and special events like weddings — places where cellphone use might be a security issue, not just an annoyance.

"In terms of growth, I think it's kind of unlimited," Dugoni said. "Because the concept goes far beyond artists. It's this idea in every modern city that you can step into a space that at any given time can be a device-free space."

In advance of Yondr's debut in Tampa Bay, we talked to Dugoni about the product's evolution and future.

How did the Tracy Morgan partnership come about?

I think they came to us the same way that pretty much all our business comes: Right through our contact form on the website. People find out about us through articles or press, or through references in the entertainment world. Someone at the tour reached out, and that's how it happened.

Why did they want to use Yondr for this tour?

In broad strokes, they said cell phones are a huge issue for them. There's obviously content control, which for comedians is huge, just the jokes not being released. But generally, when we hear from the artists or the manager, the primary thing is just the experience. What we hear from them is, it's a very bizarre experience to be up on stage and look out to a sea of smartphones. That's something that they would like to address.

What percentage of your clients use the product with the goal of enhancing the experience, versus protecting intellectual property?

Ultimately, it depends who you're talking to. When you're talking to an agent, they tend to be a little more utilitarian with it. I would say 75 percent or so of artists, it's the experience that drives the decision.

How has the product itself changed from the first shows to today?

The first one — you know the (Chinese e-commerce) website Alibaba? I just created an Alibaba account and pretended to be a real company. I went to a hardware store in San Francisco and got some fabrics, and made the first cases, kind of sewed them together, and got the guy at the hardware store to help me. I would send these samples, three or four per shipment, back and forth to these manufacturers in China with some drawings. I would take those in the back of the car and shop those around until I could get someone to use them. The first people to use it was the Stork Club in Oakland; it was a burlesque show.

Have there been any unexpected revelations on your part or an artist's part after using Yondr for a show?

The revelation is for people that come to a show. If you haven't been to a phone-free show, people just don't realize what they're missing. It's not just the moment when you're in there and the band's playing with everyone rather than looking through a smartphone. It's also the half hour before the show, when everyone is just in there talking and mingling, rather than on their phone. It's everyone drinking more and being uninhibited. It's about creating a space where it's socially acceptable to unplug.

Are there legal ramifications from separating people from their cell phones, even for just a little bit?

No, because they're never separated. And their cell phone's not digitally blocked in any way. We hear this all the time: A parent will come in and say their kid's home with a babysitter, and we go, 'Oh, that's fine. You'll feel your phone vibrate in your pocket, and you can step outside and unlock it and use it there.' It's just like a smoking/nonsmoking zone.

So if people were to challenge it and say, 'No, I have a right to carry a phone, period' — that would just be an issue with the venue?

Right. It's like anything: There are certain rules to the show. A lot of people said, 'Well, don't you get a ton of pushback when people come in the door? People's phones are like extra limbs.' Early on, just going out and being at a lot of shows, I realized that people were ready for it. If you just present it in a way that it's a fair deal, people are fine. It's only the tech nerds who think that people aren't ready for it, because they're more or less interpreting everything through a screen.